This invention relates to triaxial weaving machines of the type disclosed in U.S. Pat. No. 3,999,578 of common ownership with the instant application. More specifically, the invention relates to improvements over the heddle inventions disclosed in U.S. Pat. Nos. 3,965,939; 3,985,160; and 4,040,451, all of common ownership with the instant application.
Prior art heddles for triaxial weaving machines which are presently in use are typically made of an elongate strip material and have a rounded nose portion provided with a warp strand guide opening therethrough. The nose portions are typically of lesser thickness than at least the major portion of the heddle and are partially offset on respective sides of the warp strand guide opening to avoid abrading a warp strand passing alongside the nose portion and through the guide opening during weaving and to maintain the warp strands substantially within the thickness dimension of the major portion of their respective heddles. Heretofore it has been necessary to provide nose portions which are reduced in thickness so that this offset can be provided without the offset portions extending beyond the sides of the heddle so as to reduce the likelihood of interference of opposing heddles during shedding.
Several problems have been encountered in using heddles of this type. In certain instances when misalignments occur the thin nose portion has caused abrading or piercing of warp strands carried by heddles in an opposing row during shedding operations. Also, the thin nose portions are susceptible to damage in the event of collision with opposing heddles during shedding. In addition, while the offset portions reduce warp strand abrasion due to movement of the warp strands through the guide opening the configuration of the opening and offset portions still caused abrasion of warp strands as the heddles move back and forth during shedding.
In any weaving operation it is important to minimize damage to the warp strands so that a quality fabric can be produced. It is also important to avoid downtime due to damaged heddles which necessarily reduces the overall efficiency of the weaving operation. In this connection it is apparent that the design of the heddle and, particularly, the warp strand guide opening is critical.